The present invention relates generally to messaging and more particularly to a universal messaging center or mailbox that notifies subscribers of any type of message that is waiting for them, for example, voice mail, fax mail, e-mail, etc., and allows subscribers to retrieve and respond to the messages in formats independent not only of each other but also of the format in which the message was originally transmitted.
The trend in the telecommunications industry is toward providing a wide variety of information and communication services, or messaging services, over various communications networks to remote subscribers having diverse analog and digital communications equipment. These messaging services might include voice messaging, facsimile messaging, electronic mail, electronic document interchange, interactive voice response, audio text, speech synthesis, speech recognition, video messaging, video mail, etc.
To provide these messaging services, different types of communications equipment and processing protocols connect to a single host system or messaging center that provides the messaging services. The messaging center performs protocol conversions between the format employed by the messaging center and the various telecommunications formats employed by the diverse subscriber equipment.
Companies that provide messaging services over the public telephone network traditionally use hardwired transceiving and protocol conversion equipment dedicated to a particular type of equipment and communications format and protocol. Unfortunately, this approach suffers from high costs and lack of flexibility and adaptability. The disadvantages arise because dedicated hardware cannot be readily modified to increase data throughput, or handle communication protocols from new telecommunications equipment or services. Supporting multiple types of messaging services for diverse communications equipment thus requires costly module replacements and new designs for dedicated hardware.
Recently, some developers have proposed digital signal processing and multimedia interfaces to process the communication trunk lines. For example, U.S. Pat. No. 5,497,373 to Hulen et al. describes a system with a host messaging center that supports numerous types of messaging applications and makes the necessary protocol conversions for different telecommunications protocols corresponding to various types of telecommunications media. The system uses multiple digital signal processors to perform real time protocol conversions between the different telecommunication protocols and the protocol of the host messaging center.
FIG. 1 is a block diagram showing how Hulen et al.'s messaging system might connect to multimedia subscribers through various public and private communications networks 1100, including, for example, a public switched telephone network (PSTN), a public cellular or mobile telephone network (PLMN), and a packet switched public data network (PSPDN) . The messaging system includes telephony front end equipment 1200, multimedia interface 1300, and host messaging center 1400.
Telephony front end 1200 interfaces to communications networks 1100 and provides the necessary interface between a subscriber's voice or data channel from communications network 1100 and the messaging system. Multimedia interface 1300 performs protocol conversions of the information received in various telecommunications formats so host messaging center 1400 can process and store the information in the host's data processing and storage format, typically a compressed data format.
Once converted, host messaging center 1400 processes the relevant messaging information extracted from the communications channel to deliver the particular messaging or telephony service requested by the subscriber. Multimedia interface 1300 then converts the information for responding to the subscriber's service request back into the communications protocol format used by the subscriber, and transmits the converted information to the subscriber via telephony front end 1200 and communications network 1100.
Multimedia interface 1300 includes several parallel digital signal processors dynamically allocated to handle different types of protocol conversion for multiple communications channels. Host messaging center 1400 downloads appropriate protocol conversion algorithms to selected digital signal processors depending upon the type of services required by a particular subscriber. The selected digital signal processors convert and store the information in the format of host messaging center 1400 so host messaging center 1400 can process the information according to the particular messaging service requested by the subscriber. The subscriber retrieves the information in the communications protocol format used by the subscriber.
With this system, a subscriber's responses to the retrieved information were limited to only the precise formats that the information was stored and retrieved. This limited the subscriber's options to retrieve and respond to messages by not allowing use of other telecommunications equipment having different or multiple formats.
Therefore, a need exists to take advantage of the capabilities of current telecommunications equipment to provide subscribers with greater flexibility in the formats of retrieval and responses to messages.